2 * firewall3 - 3rd OpenWrt UCI firewall implementation
4 * Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22 static struct fw3_option default_opts[] = {
23 FW3_OPT("input", target, defaults, policy_input),
24 FW3_OPT("forward", target, defaults, policy_forward),
25 FW3_OPT("output", target, defaults, policy_output),
27 FW3_OPT("drop_invalid", bool, defaults, drop_invalid),
29 FW3_OPT("syn_flood", bool, defaults, syn_flood),
30 FW3_OPT("synflood_protect", bool, defaults, syn_flood),
31 FW3_OPT("synflood_rate", limit, defaults, syn_flood_rate),
32 FW3_OPT("synflood_burst", int, defaults, syn_flood_rate.burst),
34 FW3_OPT("tcp_syncookies", bool, defaults, tcp_syncookies),
35 FW3_OPT("tcp_ecn", bool, defaults, tcp_ecn),
36 FW3_OPT("tcp_westwood", bool, defaults, tcp_westwood),
37 FW3_OPT("tcp_window_scaling", bool, defaults, tcp_window_scaling),
39 FW3_OPT("accept_redirects", bool, defaults, accept_redirects),
40 FW3_OPT("accept_source_route", bool, defaults, accept_source_route),
42 FW3_OPT("custom_chains", bool, defaults, custom_chains),
43 FW3_OPT("disable_ipv6", bool, defaults, disable_ipv6),
48 check_policy(struct uci_element *e, enum fw3_target *pol, const char *name)
50 if (*pol == FW3_TARGET_UNSPEC)
52 warn_elem(e, "has no %s policy specified, defaulting to DROP", name);
53 *pol = FW3_TARGET_DROP;
55 else if (*pol > FW3_TARGET_DROP)
57 warn_elem(e, "has invalid %s policy, defaulting to DROP", name);
58 *pol = FW3_TARGET_DROP;
63 fw3_load_defaults(struct fw3_state *state, struct uci_package *p)
65 struct uci_section *s;
66 struct uci_element *e;
67 struct fw3_defaults *defs = &state->defaults;
71 defs->syn_flood_rate.rate = 25;
72 defs->syn_flood_rate.burst = 50;
73 defs->tcp_syncookies = true;
74 defs->tcp_window_scaling = true;
75 defs->custom_chains = true;
77 uci_foreach_element(&p->sections, e)
79 s = uci_to_section(e);
81 if (strcmp(s->type, "defaults"))
86 warn_elem(e, "ignoring duplicate section");
90 fw3_parse_options(&state->defaults,
91 default_opts, ARRAY_SIZE(default_opts), s);
93 check_policy(e, &defs->policy_input, "input");
94 check_policy(e, &defs->policy_output, "output");
95 check_policy(e, &defs->policy_forward, "forward");
100 fw3_print_default_chains(enum fw3_table table, enum fw3_family family,
101 struct fw3_state *state)
103 struct fw3_defaults *defs = &state->defaults;
104 const char *policy[] = {
116 case FW3_TABLE_FILTER:
117 fw3_pr(":INPUT %s [0:0]\n", policy[defs->policy_input]);
118 fw3_pr(":FORWARD %s [0:0]\n", policy[defs->policy_forward]);
119 fw3_pr(":OUTPUT %s [0:0]\n", policy[defs->policy_output]);
121 if (defs->custom_chains)
123 fw3_pr(":input_rule - [0:0]\n");
124 fw3_pr(":output_rule - [0:0]\n");
125 fw3_pr(":forwarding_rule - [0:0]\n");
128 fw3_pr(":delegate_input - [0:0]\n");
129 fw3_pr(":delegate_output - [0:0]\n");
130 fw3_pr(":delegate_forward - [0:0]\n");
131 fw3_pr(":reject - [0:0]\n");
132 fw3_pr(":syn_flood - [0:0]\n");
136 if (defs->custom_chains)
138 fw3_pr(":prerouting_rule - [0:0]\n");
139 fw3_pr(":postrouting_rule - [0:0]\n");
143 case FW3_TABLE_MANGLE:
144 fw3_pr(":mssfix - [0:0]\n");
148 if (!defs->drop_invalid)
149 fw3_pr(":notrack - [0:0]\n");
155 fw3_print_default_rules(enum fw3_table table, enum fw3_family family,
156 struct fw3_state *state)
159 struct fw3_defaults *defs = &state->defaults;
160 const char *chains[] = {
168 case FW3_TABLE_FILTER:
169 fw3_pr("-A INPUT -i lo -j ACCEPT\n");
170 fw3_pr("-A OUTPUT -o lo -j ACCEPT\n");
172 for (i = 0; i < ARRAY_SIZE(chains); i++)
174 fw3_pr("-A %s -m conntrack --ctstate RELATED,ESTABLISHED "
175 "-j ACCEPT\n", chains[i]);
177 if (defs->drop_invalid)
179 fw3_pr("-A %s -m conntrack --ctstate INVALID -j DROP\n",
186 fw3_pr("-A syn_flood -p tcp --syn");
187 fw3_format_limit(&defs->syn_flood_rate);
188 fw3_pr(" -j RETURN\n");
190 fw3_pr("-A syn_flood -j DROP\n");
191 fw3_pr("-A INPUT -p tcp --syn -j syn_flood\n");
194 if (defs->custom_chains)
196 fw3_pr("-A INPUT -j input_rule\n");
197 fw3_pr("-A OUTPUT -j output_rule\n");
198 fw3_pr("-A FORWARD -j forwarding_rule\n");
201 fw3_pr("-A INPUT -j delegate_input\n");
202 fw3_pr("-A OUTPUT -j delegate_output\n");
203 fw3_pr("-A FORWARD -j delegate_forward\n");
205 fw3_pr("-A reject -p tcp -j REJECT --reject-with tcp-reset\n");
206 fw3_pr("-A reject -j REJECT --reject-with port-unreach\n");
208 if (defs->policy_input == FW3_TARGET_REJECT)
209 fw3_pr("-A INPUT -j reject\n");
211 if (defs->policy_output == FW3_TARGET_REJECT)
212 fw3_pr("-A OUTPUT -j reject\n");
214 if (defs->policy_forward == FW3_TARGET_REJECT)
215 fw3_pr("-A FORWARD -j reject\n");
220 if (defs->custom_chains)
222 fw3_pr("-A PREROUTING -j prerouting_rule\n");
223 fw3_pr("-A POSTROUTING -j postrouting_rule\n");
227 case FW3_TABLE_MANGLE:
228 fw3_pr("-A FORWARD -j mssfix\n");
232 if (!defs->drop_invalid)
233 fw3_pr("-A PREROUTING -j notrack\n");
239 fw3_print_flush_rules(enum fw3_table table, enum fw3_family family,
240 struct fw3_state *state, bool complete)
244 case FW3_TABLE_FILTER:
245 fw3_pr(":INPUT ACCEPT [0:0]\n");
246 fw3_pr(":OUTPUT ACCEPT [0:0]\n");
247 fw3_pr(":FORWARD ACCEPT [0:0]\n");
255 case FW3_TABLE_MANGLE:
263 fw3_pr("-D FORWARD -j mssfix\n");
264 fw3_pr("-F mssfix\n");
265 fw3_pr("-X mssfix\n");
277 fw3_pr("-D PREROUTING -j notrack\n");
278 fw3_pr("-F notrack\n");
279 fw3_pr("-X notrack\n");